Black 5mm female and two yellow 3mm male connectors. Works with the following Dogtra Dog Training Collars:
175NCP (Serial Number less than 103471)
200NCP (Serial Number less than 111361)
202NCP (Serial Number less than 101961)/plus 3-3 splitter
1800NC (Serial Number less than 100121)
1802NC (Serial Number less than 100101)/plus 3-3 splitter
1803NC (Serial Number less than 100101)/plus a 3-3 splitter
1804NC (Serial Number less than 100126)/plus (2) 3-3 splitters